This invention relates to a method of providing a visual representation of the runout of a shaft and more particularly to a method of presenting a visual representation of the runout of the shaft forming the rotor of a steam turbine.
Shaft runout or the deviation of the outer periphery of the shaft from a true circle as the shaft is rotated has been found utilizing a dial indicator which is fixed next to a rotating shaft and has a point which contacts the shaft as the shaft rotates, the point follows the peripheral surface and a needle moves on a calibrated dial face to indicate the deviation of the peripheral surface with respect to a true circle. While this method is simple and accurate, reading a dial is difficult if the shaft is rotating and the operator must record the data relative to some angular position of the shaft or only the maximum runout can be recorded.